Ultra strong coupling regime.

In the so called "ultra strong coupling regime", the coupling strength of an electron excitation to a photonic mode can become very large and even comparable to the individual excitation energies. A range of new phenomena are predicted in this regime. We could demonstrate the strongest light matter interaction to date, by coupling a cyclotron transition of a 2D electron gas to a cavity. (15.03.2012).

These results are published in Science 335, pp. 1323-1326.